A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.
Couplings are used to connect pipes to pipes, or pipes to fittings such as valves or meters. Couplings can thus facilitate end-to-end connection of pipe sections, or they can route the pipe sections at particular angles. For example, couplings can be employed to change the direction of piping, such as by 45° or 90°. In addition, couplings can be employed to branch or split piping in different directions. For example, a single pipe section can be connected by a T-fitting or a Y-fitting, each of which branches that pipe section into two separate pipe sections. Other fittings can branch a single pipe section into more than two separate pipe sections.
Couplings preferably are easy and quick to use and are relatively inexpensive. Moreover, the couplings typically need to provide a watertight or airtight fitting. The couplings of the present invention could be used in piping installations which convey liquids or liquid slurries, i.e. sewerage for example, and they can also be used for piping gases. The couplings should also provide secure connection to the ends of the pipe sections or other fittings to which they are connected.
Couplings are usually exposed to the fluid carried within the piping installations to which the couplings are fitted. Moreover, the pipe couplings are often exposed to external conditions such as wind and rain, dust and grime etc. Accordingly, in the past, some pipe couplings have been manufactured from non-ferrous metal to prevent rusting and corrosion. Brass has been one metal employed for that purpose. While the use of brass for the manufacture of pipe couplings has been effective in resisting rust and corrosion, a drawback with brass is that it is both relatively heavy and in more recent times, expensive. The weight of brass does not affect the actual performance of a brass coupling or cause difficulties in installation, but rather, the weight adds cost when the couplings are transported in bulk. Combined with the increasing cost of brass metal, the cost of brass fittings is becoming prohibitive.
Moreover, when a pipe coupling is employed in piping installations that carry drinking water, the exposure of that water to the brass material can taint the flavour of the water unacceptably. In addition, it has been recognised that metals can contain potentially harmful agents such as lead, which can leech from the metal into the fluid carried within the piping installation. Because of this, certain countries have introduced regulations limiting the content of such agents in the materials used in pipe couplings. As a result, in order to satisfy the regulations, more expensive metal fittings have become necessary.
The present invention aims to provide a pipe coupling, which provides advantages over certain types of couplings in present use. Applicant is hopeful that the present invention can provide cost and weight savings compared to some pipe couplings in use presently, and/or potentially can also reduce the likelihood of the flavour of drinking water being tainted as described above, and/or reduce the likelihood of potentially harmful agents leeching into the fluid carried within the piping installation.